Insulin, a hormone produced by the pancreas, plays a central role in managing blood glucose levels for individuals with diabetes. It acts as a key, unlocking cells to allow sugar from the bloodstream to enter and be used for energy. Maintaining the effectiveness of insulin relies heavily on proper storage, as this delicate medication is sensitive to environmental conditions, particularly temperature extremes.
How Freezing Alters Insulin
Freezing significantly damages insulin, primarily by altering its protein structure. Insulin is a protein, and like many proteins, its biological function depends on a specific three-dimensional shape. When insulin solutions freeze, water molecules form ice crystals, which can physically disrupt this delicate protein structure. This process is known as denaturation, where the protein unfolds or breaks down, rendering it unable to function as intended.
The extreme cold can also cause insulin molecules to crystallize, a permanent change that destroys their biological function. Even if the insulin thaws and appears normal, its molecular integrity is permanently compromised, leading to a loss of effectiveness. Freezing can also lead to visible changes, such as the formation of clumps, cloudiness, or white particles, though some insulin types are naturally cloudy.
Risks of Using Frozen Insulin
Using insulin that has been frozen and then thawed carries significant health risks because its ability to lower blood sugar is compromised. The structural damage caused by freezing prevents the insulin from properly facilitating glucose uptake into cells. This ineffectiveness can lead to hyperglycemia, which is dangerously high blood sugar.
Uncontrolled high blood sugar can manifest in symptoms such as increased thirst, frequent urination, fatigue, and blurred vision. In severe instances, prolonged hyperglycemia can progress to diabetic ketoacidosis (DKA), a serious complication that requires immediate medical attention. This can lead to unpredictable blood sugar levels and potentially worsen existing long-term complications of diabetes.
Protecting Your Insulin Supply
Proper storage is important for maintaining insulin integrity and preventing it from freezing. Unopened insulin should be stored in a refrigerator at temperatures between 36°F and 46°F (2°C and 8°C). This temperature range ensures the medication remains stable until its expiration date.
To avoid freezing, never store insulin directly next to freezer compartments or in direct contact with ice packs. The freezing point of insulin is similar to water, at 32°F (0°C), so if water freezes, insulin likely will too. If insulin is suspected to have frozen, it should be discarded immediately.